Effect of antithrombin III on neutrophil deformability

As the spherical diameter of pulmonary capillaries is smaller than that of neutrophils, increased neutrophil stiffness or conversely, decreased neutrophil deformability is a key step in the initial sequestration of neutrophils within the lungs during inflammatory processes. Antithrombin III (AT) is known to exert a therapeutic effect against disseminated intravascular coagulation, and accumulating evidence suggests that AT also has anti-inflammatory properties. The mechanisms of its anti-inflammatory effects remain unclear, but in a rat endotoxin model, AT apparently inhibited neutrophil sequestration in the lung. In the present in vitro study, therefore, we examined the effect of AT on the deformability of human neutrophils and correlated those findings with their F-actin content. Isolated human neutrophils were stimulated with formyl-Met-Leu-Phe (1 muM, 2 min) in the presence or absence of the alpha, beta, or low heparin-affinity isoforms of AT (1 IU/ml, 20 min), and deformability was evaluated using a filter assay system. Neutrophils were also stained with fluorescein isothiocyanate-phalloidin and subjected to a fluorescein-activated cell sorter scan to assess F-actin content. The results showed that pretreatment with any of the three AT isoforms similarly inhibited the decreased neutrophil deformability and increased F-actin content of stimulated cells. Notably, heparinase had no effect on deformability or F-actin content in the presence or absence of AT, which was somewhat unexpected, as heparin sulfate proteoglycans likely function as AT receptors. These findings suggested that AT inhibits the increase in neutrophil stiffness seen during inflammatory processes by inhibiting actin polymerization via a heparin-independent pathway.     

Rehabilitation after arthroscopic anterior cruciate ligament reconstruction

Rehabilitation is an important part of therapy in patients who have had arthroscopic anterior cruciate ligament reconstruction. A well-designed rehabilitation program avoids potential graft damage and speeds up patients' return to their full function level. The course of rehabilitation depends on the type of surgery, mode of fixation and possible co-existing injury to the knee's soft tissues. The rehabilitation program presented here is based on the present-day knowledge of neurophysiological and biomechanical principles and is divided into five phases. In the pre-operative phase (I), the main objective is to prepare patients for surgery in terms of maximum muscle strength and range of motion. It also includes providing full information on the procedure. In the early post-operative phase (II) we are concerned with pain alleviation and reduction of knee edema. After suture removal we begin with soft techniques for the patella and post-operative physical therapy to reduce scarring. In the next post-operative phase (III) patients are able to walk with their full weight on the extremity operated on, and we continue doing exercises that improve flexor/extensor co-contraction. In this phase we also begin with exercises improving the patient's proprioceptive and sensorimotor functions. In the late post-operative phase (IV) we go on with exercises promoting proprioception of both lower extremities with the aim of increasing muscle control of the knee joints. In the convalescent phase (V) patients gradually return to their sports activities.     

Changes in the contractile responses to carbachol and in the inhibitory effects of verapamil and nitrendipine on isolated smooth muscle preparations from rats subchronically exposed to Co2+ and Ni2+

Male Wistar rats were exposed to subtoxic doses of Co²⁺ or Ni²⁺, receiving Co(NO₃)₂ or NiSO₄ with drinking water for 30 days. No significant differences in the body weight and no visible changes in the behaviour of the controls and experimental animals were established. Cumulative concentration-effect curves for carbachol were obtained in ileum and trachea isolated from control and Co²⁺- or Ni²⁺-treated rats. The effect of the Ca²⁺ antagonists on the carbachol-induced contractions was studied by adding increasing concentrations of verapamil or nitrendipine to the bath solution 20 min prior to carbachol. The results showed that exposure of rats to subtoxic doses of Co(NO₃)₂ or NiSO₄ altered the contractile responses to carbachol. The changes in the pD₂ values and the shift to the left of the concentration-effect curves suggest a higher sensitivity to carbachol in preparations from the ileum of Co²⁺- or Ni²⁺-exposed rats. The tracheal strips isolated from control and heavy metal-treated rats showed a less potent sensitiveness to carbachol as compared to the ileal segments. An opposite tendency for decreased cholinergic reactivity was observed in tracheal strips from Co²⁺- and Ni²⁺-treated animals. The inhibitory effect of the Ca²⁺-antagonists on the contractility of ileal preparations from Co²⁺-treated rats increased at all concentrations of verapamil and at the highest concentration of nitrendipine, but decreased at lower concentrations of nitrendipine. The effect of verapamil on the preparations from Ni²⁺-exposed rats was unchanged or even decreased at higher verapamil concentrations. The inhibitory effect of nitrendipine on preparations from Ni²⁺-exposed rats decreased at the lowest concentration but increased at the highest concentration of the blocker. In Co²⁺- or Ni²⁺-treated tracheal preparations verapamil inhibited the contractions induced by low and medium concentrations of carbachol but increased the maximal contractile responses to high concentrations of carbachol.     

Public health control of hyperhomocysteinemia and its consequences

The etiological role of hyperhomocysteinemia in the origin of neural-tube defects was proved, therefore a mandatory flour folic acid fortification program was introduced in the USA since January 1, 1998. In Hungary one kind of breads was fortified with folic acid, vitamin B12 and vitamin B6. The Hungarian randomised controlled trials of periconceptional folic acid containing micronutrient-combination supplementation also indicated a reduction in the occurrence of congenital cardiovascular malformations, urinary tract's defects and congenital limb deficiencies and these findings were confirmed by US teams. Recent studies showed a positive association between cardiovascular diseases and hyperhomocysteinemia as well, thus it is considered as an independent etiological factor in the pathogenesis of ischemic heart diseases, stroke, deep vein thrombosis, in addition of vascular diseases in the placenta during pregnancy. Other studies showed that hyperhomocysteinemia is more prevalent in demented patients and in persons with impaired cognitive performance. Some association was also found between hyperhomocysteinemia and cancers (e.g. colon). There is strong evidence that four vitamins B, such as vitamin B11 (folate-folic acid), vitamin B12, B2 and B6 can reduce the level of serum homocysteine and subsequently neural-tube defects. In addition the results of intervention studies indicated a protective effect of folic acid and other vitamins B for some other congenital abnormalities, cardiovascular diseases, senile dementia and cancers. The flour fortification with these water-soluble vitamins B is appropriate for an effective public health program for the primary prevention of these hyperhomocysteinemia-related disorders. There is no real risk for side effects on the basis of available US, Canadian and Hungarian experiences. In conclusion an urgent task is to introduce a mandatory flour fortification program in Hungary.     

Human dendritic cells genetically engineered to express cytosolically retained fragment of prostate-specific membrane antigen prime cytotoxic T-cell responses to multiple epitopes

The ability of two plasmid DNA vaccines to stimulate lymphocytes from normal human donors and to generate antigen-specific responses is demonstrated. The first vaccine (truncated; tPSMA) encodes for only the extracellular domain of prostate-specific membrane antigen (PSMA). The product, expressed following transfection with this vector, is retained in the cytosol and degraded by the proteasomes. For the "secreted" (sPMSA) vaccine, a signal peptide sequence is added to the expression cassette and the expressed protein is glycosylated and directed to the secretory pathway. Monocyte-derived dendritic cells (DCs) are transiently transfected with either sPSMA or tPSMA plasmids. The DCs are then used to activate autologous lymphocytes in an in vitro model of DNA vaccination. Lymphocytes are boosted following priming with transfected DCs or with peptide-pulsed monocytes. Their reactivity is tested against tumor cells or peptide-pulsed T2 target cells. Both tPSMA DCs and sPSMA DCs generate antigen-specific cytotoxic T-cell responses. The immune response is restricted toward one of the four PSMA-derived epitopes when priming and boosting is performed with sPSMA. In contrast, tPSMA-transfected DCs prime T cells toward several PSMA-derived epitopes. Subsequent repeated boosting with transfected DCs, however, restricts the immune response to a single epitope due to immunodominance.     

CYP1A1 and GSTM1 genetic polymorphisms and lung cancer risk in Caucasian non-smokers: a pooled analysis

Polymorphisms for genes encoding the metabolic enzymes cytochrome P450 1A1 (CYP1A1) and glutathione S-transferase M1 (GSTM1) might contribute to the variability in individual susceptibility to lung cancer. The role of CYP1A1 and GSTM1 in lung carcinogenesis might be more important at low levels of exposure to carcinogens. Non-smokers represent a population at low exposure, however, they are often overlooked because of the small number of cases. We therefore conducted a pooled analysis of 14 case-control studies on lung cancer in Caucasian non-smokers with comparable information on genetic polymorphisms included in the International Collaborative Study on Genetic Susceptibility to Environmental Carcinogens. We pooled the raw data from a total of 302 cases and 1631 controls with random effects models. We also evaluated the possibility of inclusion bias and conducted influence analyses. The odds ratio (OR) of lung cancer for the variant CYP1A1 Ile(462)Val polymorphism (Ile/Val, Val/Val) was 2.99 [95% confidence interval (95%CI) 1.51-5.91]; this effect was stronger on lung adenocarcinoma (OR 4.85, 95%CI 2.03-11.6). After excluding outlying or imprecise studies, we did not observe a significant effect of the CYP1A1 MspI (T(3801)C) polymorphism or GSTM1 null genotype (OR 1.20, 95%CI 0.89-1.63). Furthermore, our analyses suggested a combined effect of the CYP1A1 Ile(462)Val polymorphism and GSTM1 null genotype. The OR for the combination of the CYP1A1 Ile(462)Val variant and GSTM1 null genotype was 4.67 (95%CI 2.00-10.9) compared with the concurrent presence of the CYP1A1 wild-type and GSTM1 non-null genotype. We did not observe a modification of the effect of the GSTM1 null genotype according to exposure to environmental tobacco smoke and urban/rural residence. Our study therefore suggests that the CYP1A1 Ile(462)Val variant allele might play a role in lung carcinogenesis among non-smokers, possibly in combination with the GSTM1 null genotype.     

OASIS-HT: design of a pharmacogenomic dose-finding study

Experimental evidence and observations in humans strongly support an interactive role of mutated alpha-adducin, sodium (Na(+))/potassium (K(+))-adenosine triphosphatase (ATPase) activity and endogenous ouabain in Na(+) homeostasis and the pathogenesis of hypertension. The Ouabain and Adducin for Specific Intervention on Sodium in HyperTension (OASIS-HT) trial is an early Phase II dose-finding study, which will be conducted across 39 European centers. Following a run-in period of 4 weeks without treatment, eligible patients will be randomized to one of five oral doses of rostafuroxin consisting of 0.05, 0.15, 0.5, 1.5, or 5.0 mg/day. Each dose will be compared to a placebo in a double-blind crossover experiment with balanced randomization. Treatment will be initiated with the active drug and continued with placebo or vice versa. Each double-blind period will last 5 weeks. The primary end point is the reduction in systolic blood pressure defined as the average of three clinic readings with the patient in the sitting position. Secondary end points include the reduction in diastolic blood pressure on clinic measurement, the decrease in the 24-h blood pressure, and the incidence of end points related to safety. Secondary objectives are to investigate the dependence of the blood pressure-lowering activity on the plasma concentration of endogenous ouabain and the genetic variation of the enzymes involved in the metabolism of this hormone, and the adducin cytoskeleton proteins. Eligible patients will have Grade I or II systolic hypertension without associated conditions and no more than two additional risk factors. In conclusion, OASIS-HT is a combination of five concurrent crossover studies, one for each dose of rostafuroxin to be studied. To our knowledge, OASIS-HT is the first Phase II dose-finding study in which a genetic hypothesis is driving primary and secondary end points.